Spices are not so nice for people who are allergic to them. The problem is rare but may be under-diagnosed, one doctor says. / Jupiterimages

by Kim Painter, Special for USA TODAY

by Kim Painter, Special for USA TODAY

Dennis Wissing, 58, of Shreveport, La., has a severe food allergy - one that causes him to break out in internal hives on his esophagus. But the problem isn't peanuts or shellfish or one of the other common food allergies: It's garlic.

Luckily, he says, he and his wife are good home cooks: "Avoiding garlic in a restaurant is just about impossible."

While Wissing is not alone, his plight isn't common, either: Allergies to spices - any of the fresh or dried, ground, toasted or otherwise processed plants we use to flavor our foods - have been found in just 2% of all adults with food allergies in studies.

"We think it is rare," says Sami Bahna, chief of allergy and immunology at Louisiana State University Health Sciences Center, Shreveport. But Bahna, who is working to raise the profile of spice allergies, says: "I strongly believe that it is markedly under-diagnosed because of the great difficulty in identifying it."

Bahna took his case to colleagues at an annual meeting of the American College of Allergy, Asthma & Immunology this week. His aim, he says, is to urge more doctors to do the "detective work" often needed to diagnose these allergies and help patients find relief.

Sleuthing is often needed, he says, because there are no skin or blood tests for many spices. Garlic is an exception: Wissing, who is an assistant dean at Bahna's university, says the doctor diagnosed him with a panel of food skin tests that included garlic. It was the only thing that made his skin swell.

But Bahna says a more typical story is a patient who doesn't react to any standard food test and who is baffled by on-and-off reactions to certain foods. "When he has chicken at home, he's fine, but when he has a certain chicken dish at a restaurant, he has trouble," Bahna says. More than once, Bahna has called a restaurant and said that he has a "patient who loves your restaurant and loves a certain dish, but gets hives every time he eats it." Chefs are usually willing to share their ingredient list to help solve the mystery and keep a customer safe, he says.

The spices to blame, he says, can be anything from anise to turmeric, but the most common culprits vary, he says, based on diet. Onion and garlic allergies are probably relatively common in the United States, he says, but among some ethnic groups, cumin or coriander might prevail.

Who's most at risk? People who have other allergies, especially to mugwort and birch pollens, appear especially vulnerable, Bahna says. So do people who work with food, such as restaurant chefs, home cooks, factory and farm workers, and people who make or use certain cosmetic and home products that contain spices. Bahna says he had one patient who was breaking out in hives every morning until he used a different bathroom in his home - one that didn't have the spice-scented air freshener used in his master bathroom.

While it's good to keep an eye out for these allergies, it's important to note that many physical reactions to spices - such as the runny nose many people get when they eat spicy foods or the sneezing caused by a whiff of pepper - are not allergic reactions, says Stanley Fineman, president of the allergy college and a physician at the Atlanta Allergy & Asthma Clinic. A true allergic reaction to any food might involve hives, swelling, digestive distress or wheezing. In rare cases, life-threatening body-wide reactions known as anaphylaxis can occur.